If i change the cellclass in the brain file, it at least compiles and runs, although it does not work at all as there are no spikes generated.So all in all, what is the recommended (or better: correct) way of doing this?

At first, I recomment you tag the question as Neurorobotics, so that the relevant people see the question

Apart from that, this is a good example of a bad error message. Are you running the NRP locally? If so, could you have a look in the console log to find a stack trace?

Otherwise, what the NRP does is to simply output the original error message, which in case of e.g. a KeyError is just the key that was used. So somewhere, you were accessing a "wavetest" of something (perhaps a dictionary) that does has no such entry. For a better help, I would need a stack trace.

Hey,my bad, i forgot to tag it...Yes, i am running the NRP locally and "wavetest" is actually just the name of the python function in my TF. Just a heads up, there is a lot off log dump following, sry in advance

This seems to be a very odd error. The problem is that you apparently want to connect a Poisson generator to a neuron population that does not support any receptor types. Did you use a custom neuron model?

From the three error logs, the interesting one only is the first. The second log is an internal ROS log that somebody reset the connection but that happens basically because the Transfer Function initialization could not be completed. The third error is basically a propagation of the first one in the backend component.

yeah, now I see it. You are trying to connect a Poisson generator to a Poisson generator. That basically doesn't work in nest, because the Poisson generator neuron model does not accept incoming spikes. I guess what you really want is to connect the TF to different neurons?

Hey Georg,yeah, i figured as much, but the NRP documentation is kind of quirky regarding that stuff... so i need a spike source in general (no need for anything special, no timings etc...); how would i go about it then? It seems if i switch the sim.SpikeSourcePoisson to something else (IF_curr_exp or comparable) (and keep the nrp.poisson in the TF), nothing happens (spiking wise).

You should indeed connect the TF using a Spike Source mapping to a neuron of your choice. The only thing, the default weight of a Poisson generator is pretty low and we only generate exactly one Poisson generator. For a IF_curr_exp neuron, this is by far not enough in order to achieve a meaningful effect because the weight is only 0.00015. What you can do is either change the weight of your Poisson generator (for example 5.0), use multiple Poisson generators or use a high firing rate (for example 1000). Using multiple Poisson generators is currently awful, we really need to change that. I will file a bug in the developer backlog for this, since it is also particularly easy to accomplish.

Or you could use other neuron models. The standard examples use IF_cond_alpha neurons, which are much easier to excite.